Data from: A host-adapted auxotrophic gut symbiont induces mucosal immunodeficiency (Part I)

Harnessing the microbiome to benefit human health requires an initial step
in determining the identify and function of causative microorganisms that
impact specific host physiologic functions. Here we show a functional
screen of the bacterial microbiota from mice with low intestinal
immunoglobulin A (IgA) levels; we identified a Gram-negative bacterium,
proposed as Tomasiella immunophila that induces and degrades IgA in mouse
intestine. Mice harboring T. immunophila are susceptible to infections and
show poor mucosal repair. T. immunophila is auxotrophic for the bacterial
cell wall amino sugar N-acetylmuramic acid (MurNAc). It delivers
immunoglobulin-degrading proteases into outer membrane vesicles that
preferentially degrade rodent antibodies with kappa but not lambda light
chains. This work indicates a role for symbionts in immunodeficiency,
which might be applicable to human disease.